Thoughts, tutorials, and insights
Pixel is for painting and retouching. Brush B, Eraser E, Clone J, and Wand W work on a pixel layer inside the same .oma as the vectors.
Paint lives on a pixel layer in the same stack as the vectors. If the document is vector-only, add one from the Layers menu. The paths stay paths.

Brush is B. Size is the bracket keys. Hardness is Shift plus the brackets. Eraser E, Fill K, Clone J, Smudge M. Alt-click sets the clone source.